source: trunk/src/declarative/util/qdeclarativetransitionmanager.cpp@ 944

/****************************************************************************
**
** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation ([email protected])
**
** This file is part of the QtDeclarative module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at [email protected].
** $QT_END_LICENSE$
**
****************************************************************************/

#include "private/qdeclarativetransitionmanager_p_p.h"

#include "private/qdeclarativestate_p_p.h"
#include "private/qdeclarativestate_p.h"

#include <qdeclarativebinding_p.h>
#include <qdeclarativeglobal_p.h>
#include <qdeclarativeproperty_p.h>

QT_BEGIN_NAMESPACE

DEFINE_BOOL_CONFIG_OPTION(stateChangeDebug, STATECHANGE_DEBUG);

class QDeclarativeTransitionManagerPrivate
{
public:
    QDeclarativeTransitionManagerPrivate()
    : state(0), transition(0) {}

    void applyBindings();
    typedef QList<QDeclarativeSimpleAction> SimpleActionList;
    QDeclarativeState *state;
    QDeclarativeTransition *transition;
    QDeclarativeStateOperation::ActionList bindingsList;
    SimpleActionList completeList;
};

QDeclarativeTransitionManager::QDeclarativeTransitionManager()
: d(new QDeclarativeTransitionManagerPrivate)
{
}

void QDeclarativeTransitionManager::setState(QDeclarativeState *s)
{
    d->state = s;
}

QDeclarativeTransitionManager::~QDeclarativeTransitionManager()
{
    delete d; d = 0;
}

void QDeclarativeTransitionManager::complete() 
{
    d->applyBindings();

    for (int ii = 0; ii < d->completeList.count(); ++ii) {
        const QDeclarativeProperty &prop = d->completeList.at(ii).property();
        prop.write(d->completeList.at(ii).value());
    }

    d->completeList.clear();

    if (d->state) 
        static_cast<QDeclarativeStatePrivate*>(QObjectPrivate::get(d->state))->complete();
}

void QDeclarativeTransitionManagerPrivate::applyBindings()
{
    foreach(const QDeclarativeAction &action, bindingsList) {
        if (!action.toBinding.isNull()) {
            QDeclarativePropertyPrivate::setBinding(action.property, action.toBinding.data());
        } else if (action.event) {
            if (action.reverseEvent)
                action.event->reverse();
            else
                action.event->execute();
        }

    }

    bindingsList.clear();
}

void QDeclarativeTransitionManager::transition(const QList<QDeclarativeAction> &list,
                                      QDeclarativeTransition *transition)
{
    cancel();

    QDeclarativeStateOperation::ActionList applyList = list;
    // Determine which actions are binding changes.
    foreach(const QDeclarativeAction &action, applyList) {
        if (action.toBinding)
            d->bindingsList << action;
        if (action.fromBinding)
            QDeclarativePropertyPrivate::setBinding(action.property, 0); // Disable current binding
        if (action.event && action.event->changesBindings()) {  //### assume isReversable()?
            d->bindingsList << action;
            action.event->clearBindings();
        }
    }

    // Animated transitions need both the start and the end value for
    // each property change.  In the presence of bindings, the end values
    // are non-trivial to calculate.  As a "best effort" attempt, we first
    // apply all the property and binding changes, then read all the actual
    // final values, then roll back the changes and proceed as normal.
    //
    // This doesn't catch everything, and it might be a little fragile in
    // some cases - but whatcha going to do?

    if (!d->bindingsList.isEmpty()) {

        // Apply all the property and binding changes
        for (int ii = 0; ii < applyList.size(); ++ii) {
            const QDeclarativeAction &action = applyList.at(ii);
            if (!action.toBinding.isNull()) {
                QDeclarativePropertyPrivate::setBinding(action.property, action.toBinding.data(), QDeclarativePropertyPrivate::BypassInterceptor | QDeclarativePropertyPrivate::DontRemoveBinding);
            } else if (!action.event) {
                QDeclarativePropertyPrivate::write(action.property, action.toValue, QDeclarativePropertyPrivate::BypassInterceptor | QDeclarativePropertyPrivate::DontRemoveBinding);
            } else if (action.event->isReversable()) {
                if (action.reverseEvent)
                    action.event->reverse(QDeclarativeActionEvent::FastForward);
                else
                    action.event->execute(QDeclarativeActionEvent::FastForward);
            }
        }

        // Read all the end values for binding changes
        for (int ii = 0; ii < applyList.size(); ++ii) {
            QDeclarativeAction *action = &applyList[ii];
            if (action->event) {
                action->event->saveTargetValues();
                continue;
            }
            const QDeclarativeProperty &prop = action->property;
            if (!action->toBinding.isNull() || !action->toValue.isValid()) {
                action->toValue = prop.read();
            }
        }